The effects of blanching treatment on the radical scavenging activity of white saffron (Curcuma mangga Val.)

The purpose of this research was to study the effect of blanching methods on antioxidant activity of parts and whole white saffron rhizomes. White saffron rhizomes were peeled, washed, and blanched in boiling water at 100°C, or steamed for 5, 7.5, and 10 minutes in the media of distilled water, 0.05%, and 0.1% citric acid solution. The antioxidative activity of blanched white saffron was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA) method. The total phenolic content (TPC) was determined using a Folin-Ciocalteu assay using gallic acid (GA) as a standard. White saffron rhizomes blanched at 100°C for 5 minutes in 0.05% citric acid solution showed the highest antioxidant activity with RSA of 86.57%. Antioxidant activity of the first branch of white saffron rhizome (RSA of 84.89%) showed no significant difference from the main rhizome. These findings confirmed that blanching in media containing citric acid (0.05%) resulted in increased RSA and TPC in white saffron rhizome as compared to fresh or water blanched white saffron.